Adjust validations

Author: vpodorozh

.github/workflows/php.yml

@@ -18,7 +18,7 @@ jobs:
     - uses: actions/checkout@v3
 
     - name: Validate composer.json and composer.lock
-      run: composer validate --strict
+      run: composer validate
 
     - name: Cache Composer packages
       id: composer-cache
@@ -32,6 +32,15 @@ jobs:
     - name: Install dependencies
       run: composer install --prefer-dist --no-progress
 
+    - name: PHP 7.4 compatibility
+      run: composer sniffer:php7.4
+
+    - name: PHP 8.0 compatibility
+      run: composer sniffer:php8.0
+
+    - name: PHP 8.1 compatibility
+      run: composer sniffer:php8.1
+
     # Add a test script to composer.json, for instance: "test": "vendor/bin/phpunit"
     # Docs: https://getcomposer.org/doc/articles/scripts.md